The millipedes Mycogona germanicum and Leptoiulus proximus new to the fauna of the Netherlands (Myriapoda: Diplopoda) Mycogona germanicum (Verhoef, 1892) and Leptoiulus proximus (Némec, 1896) are recorded here for the first time from the Netherlands. Of both species single specimens were found in the collection of the National Museum of Natural History (Leiden) in old soil samples. Mycogona germanicum is a central European millipede, that has been collected in May 1982 at the ‘Onderste Bos’, Eperheide (provincie of Limburg). One male specimen was collected in a litter sample in a deciduous forest. One male Leptoiulus proximus (a Northeast-European millipede) was collected in May 1990 in a nutrient-poor meadow at Voltherbroek, Weerselo (province of Overijssel). The taxonomy and European distribution of both species in Europe are treated. With these new records 49 species of millipedes are currently known to occur in the Netherlands.